Thanks, +1. On Fri, Feb 26, 2016 at 12:35 PM, Stephan Ewen <se...@apache.org> wrote:
> Hi! > > I think it is a release blocker. > > That was a change to make it possible to use Flink with SBT (and make it > easier to use it with Maven). > Just had an offline chat with Till, and we suggest the following solution: > > All libraries should be split into two projects: > - library > - library-examples > > The "library" project has the core flink dependencies as "provided" > The "library-examples" project has both the "library" and the core flink > dependencies with scope "compile" > > That way the example should run in the IDE out of the cox, and users that > reference the libraries will still get the correct packaging (include the > library in the user jar, but not additionally the core flink jars). > > Greetings, > Stephan > > > On Thu, Feb 25, 2016 at 3:45 PM, Márton Balassi <balassi.mar...@gmail.com> > wrote: > > > Issued JIRA ticket 3511 to make it referable in other discussions. [1] > > > > [1] https://issues.apache.org/jira/browse/FLINK-3511 > > > > On Thu, Feb 25, 2016 at 3:36 PM, Márton Balassi < > balassi.mar...@gmail.com> > > wrote: > > > > > Recent changes to the build [1] where many libraries got their core > > > dependencies (the ones included in the flink-dist fat jar) moved to the > > > provided scope. > > > > > > The reasoning was that when submitting to the Flink cluster the > > > application already has these dependencies, while when a user writes a > > > program against these libraries she will include the core dependencies > > > explicitly anyway. > > > > > > There is one other case of usage however, namely when someone is trying > > to > > > run an application defined in these libraries depending on the core > jars. > > > To give an example if you were to run the Gelly ConnectedComponents > > example > > > [2] from an IDE after importing Flink (or running with java -jar > without > > > including the flink fat jar in the classpath) you would receive the > > > following class not found exception as per the current master: > > > > > > Exception in thread "main" java.lang.NoClassDefFoundError: > > > org/apache/flink/api/common/ProgramDescription > > > at java.lang.ClassLoader.defineClass1(Native Method) > > > at java.lang.ClassLoader.defineClass(ClassLoader.java:760) > > > at > > java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) > > > at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) > > > at java.net.URLClassLoader.access$100(URLClassLoader.java:73) > > > at java.net.URLClassLoader$1.run(URLClassLoader.java:368) > > > at java.net.URLClassLoader$1.run(URLClassLoader.java:362) > > > at java.security.AccessController.doPrivileged(Native Method) > > > at java.net.URLClassLoader.findClass(URLClassLoader.java:361) > > > at java.lang.ClassLoader.loadClass(ClassLoader.java:424) > > > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) > > > at java.lang.ClassLoader.loadClass(ClassLoader.java:357) > > > at java.lang.Class.forName0(Native Method) > > > at java.lang.Class.forName(Class.java:264) > > > at com.intellij.rt.execution.application.AppMain.main(AppMain.java:122) > > > > > > Where the class missing in runtime is in flink-core, a transitive > > > dependency of the jars moved to the provided scope. > > > > > > Funny thing is we have tests in place to run our examples, but those > add > > > test scope dependencies re-adding the missing classes, so it is never > > > discovered. > > > > > > I agree with the original purpose of PR #1683, but also think that the > > > current state makes for very inconvenient user experience. > > > > > > I would like to open a discussion on how and when to resolve the issue > > > given the release of 1.0.0. > > > > > > 1. Is it a release blocker? > > > 2. Should the change be reverted or is it sufficient to have proper > > > documentation around it? Maybe a maven profile for explicitly for > > > developing Flink without the provided scope? > > > > > > Note that the issue was originally reported by Gábor Gévay. > > > > > > [1] https://github.com/apache/flink/pull/1683 > > > [2] > > > > > > https://github.com/apache/flink/blob/master/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/ConnectedComponents.java > > > > > > Best, > > > > > > Marton > > > > > >
